binutils/testsuite/

binutils/testsuite/
	* lib/binutils-common.exp (is_zlib_supported): New function.
	* lib/utils-lib.exp (run_dump_test): If as options include
	--compress-debug-sections and zlib is not available, report
	the test as unsupported.
	* binutils-all/compress.exp: Bail out if zlib is not available.
	* binutils-all/objdump.exp (objdump compressed debug):
	Mark unsupported if zlib is not available.
	* binutils-all/readelf.exp (readelf_compressed_wa_test): Likewise.

gas/testsuite/
	* lib/gas-defs.exp (run_dump_test): If as options include
	--compress-debug-sections and zlib is not available, report
	the test as unsupported.

ld/testsuite/
	* ld-elf/compress.exp: Bail out if zlib is not supported.
	* lib/ld-lib.exp (run_dump_test): If as options include
	--compress-debug-sections and zlib is not available, report
	the test as unsupported.